merge HDFS-3332. NullPointerException in DN when directoryscanner is trying to report bad blocks. Contributed by Amith D K.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1333589 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -468,6 +468,9 @@ Release 2.0.0 - UNRELEASED
     HDFS-3351. NameNode#initializeGenericKeys should always set fs.defaultFS
     regardless of whether HA or Federation is enabled. (atm)
 
+    HDFS-3332. NullPointerException in DN when directoryscanner is trying to 
+    report bad blocks. (Amith D K via umamahesh)
+
   BREAKDOWN OF HDFS-1623 SUBTASKS
 
     HDFS-2179. Add fencing framework and mechanisms for NameNode HA. (todd)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BPServiceActor.java

@@ -235,6 +235,9 @@ class BPServiceActor implements Runnable {
   }
 
   void reportBadBlocks(ExtendedBlock block) {
+    if (bpRegistration == null) {
+      return;
+    }
     DatanodeInfo[] dnArr = { new DatanodeInfo(bpRegistration) };
     LocatedBlock[] blocks = { new LocatedBlock(block, dnArr) };